Printing press



W. M. POLLOCK PRINTING PRESS Oct. 6, 1953.

3 Sheets-Sheet 1 Filed Sept. 29, 1949 Oct. 1953 w. M. POLLOCK ,316

' PRINTING PRESS Filed Sept. 29, 1949 3. 3/ .Z' -5. K; F M

5 Sheets-Sheet 2 Oct. 6, 1953 w. M. POLLOCK 2,654,316 v PRINTING PRESS Filed Sept. 29, 1949 3 Sheets-Sheet 3 7 q I 1 mum Patented Oct. 6, 1953 i UNITED OFFICE rf iio.

follibckfiliort mug-isn- J to American Type Folinders; 1116.: it eorpobat'icii 6! New J er'sey' Application September 29, 1949 serial i1'8,66 1 Claini'i'si (01. 16I= 282i This invention reIe eS teprmnne presses parimateiy the midpoint of 1 the Inch it r necessity. be flat bed type in which the hecipf' eatery bee anti ee in order" to bri'ngjit smooththe impression ey nqer' are con cted together the fid bf its printing stroke. by gearing for simultaneoiis operation, and the 5 s P mpldyed may causethe bed cylinder is driven b'y' powei' takn from the bed. pie harm'o'r'iic' motion in its Those familiar with the coi'is'triictiohand Op 7 Bfiloii cye1e; or may impart eration of printing presses of this general type v c a 1y d'ifierht' eleration deceleration appreciate the need to ,niaint'a ji'ri the peripheral vem'ents'; Ijheny however, the cylinspeed of the surface" or t e impression cy inder" 10 a as W1l'asthe bee, wm nrst be accelerated, the same as th'ef linear s'peed cf advancement of the bed when the'beu' is moving upon its print: ing stroke. Any relativemovement between bee and cylinder during a printing operation, of course, results the" bliirririgof' a tra nsversel'y extendingelongated a ea ofj the printed; sheet and hence in a der ctwe'prmnne' operation, Furthermore, if the construction such that any such relative" movement between members of the couple occur regularly at a: predetermined point in the travel of the bed the printing surface will be Worn diie" to repeated"slippagjbe tween the cylinder and a definitealthoilgh'iathei sfnall area of the printing form, It is; of ourse; highly important to minimize the possibility oi. the production of defective printed matter and wearof the printing surface ahd'it is the prine cipal object of the' present iiiv'ehtion'to provide" v a I I v a means for positively preventing s11 f thefo jv farq andheret" 're ina'ctive face of that relative movementjof' therhemberslofjthe'pri" cylinder gear tooth" yv1lladvance and contact ing couple of a printing press dilri'r'ig' a? printing: the rearvvardly meme octrlailing" face of the operation. 7 preeedme c tootmthe cylindei' gear momen- A means eommonly'emhidyed to effect Seen; 1:" 1y; aidvahcingfl teeter than the" bed rack by lation of the impressibnjeylindei of a" fiat bedj son the att re-sate; flywheel action or the press in synchr'onisni v'viththe movements of the a d; 9. 7 2 Sl W E W O h be It bed compr'ise'sa rack rigidly ffiounted uppiilthi 4 A I eonpt thisslig'ht rel bed and disposedin pereneiiemtc theesn'edf by d. fifiwmdifmem v ndi' a and e d movement and a circular gear rigidly moniit''d k. that the Slurfing f p th Sheet and upon the cylinder, theteeth' ffv rack nd ge r ar q cothe pr ptme w e e; i ihtermeshingas closely as may besoas tam-if Q j'q w i ht presen "invention-th re imize backlash and relativemovenieht betffeehj $Q 1"W l? Q e member of the print n the members to Whichthe'toothed'elemntsf o p p e abl h'Q Qf QQF itively respectively secured. Backlash may "e 39 h e 'm r of h ri n do S ch' mani ierj as to'preventthe trai1- in: race" of" their active tooth" or the" driven member irom leaving the forward face of the y fila'y or b klash in the gearing, and

when the teeth of rackand gear int perfectly due to' defects iii origi" l construction, or mayresuit from w usual automatic bed and cylifider U 4 ma ,4 ne ifl d vf m m r wh n signed to rint s v ral h pe hiya-if aee'eiere'hen of 'th'e diivifig' friember'on'its printand hence vsrearin the" gear'ing'coniiecting bed ing stroke first begins. The invention may have and cylinder will inevitablyoccur;v a number of" different embodiment but in the The bed of such a rees' is; or course, dr ven s ff th lflat h fd press" in which the bed is with an accelerating -decelerating monen'rege'mpositively driven and tli' Cylinder s oscillated s bypdtve'r tr 'it'diree n riom the" bed;

- th I er't e'qevieewh eh' e'con Deny movevifithth'bed alt all "tithes.

less of the specific nature ofthedriv g inea'ii employed. Thusthe bc'iyvill'start'jpn ltspr I, re; i ing stroke from a position of restahd Willb'e" a d-Mb but which is so supported that it may move forwardly in the direction of the printing stroke relatively to the bed when deceleration of the bed first begins to take place.

This weight or inertia, device is connected, by means of suitable motion multiplying levers, to a rack which is mounted upon the bed for sliding movement in a direction parallel to the direction of the bed motion. Forward movement of the weight results in slight rearward movement of the rack, relatively to the bed, and the teeth of this sliding rack are in constant mesh, in all positions of adjustment, with the teeth of a secondary gear or gear segment rigidly mounted upon the cylinder. Hence a force is transmitted by the sliding rack to thecylinder tending to rotate the cylinder in a direction opposite to that in which the cylinder is already rotating about its axis and the application of this force causes the rearwardly facing surface of the then active tooth of the cylinder main gear to maintain close contact with the forwardly facing surface of the then active tooth of the main rack so that separation of these surfaces and relative movement of bed and cylinder is prevented. As the forward movement of the inertia device associated with the bed is caused initially by deceleration of the bed, continued deceleration of the bed will have the effect of maintaining the inertia device active in its application of force to the sliding rack so that relative movement of cylinder and bed due to backlash or play in the connecting gearing is prevented during the entire period of bed deceleration, or until the printing stroke has been completed. When the motion of the bed is reversed and it decelerates during the final period of its non-printing stroke the inertia device will, of course, move in the opposite direction relatively to the bed and pressure of the teeth of the sliding rack against the mating teeth of the cylinder gear or gear segment will be relieved. The printing couple, however, upon the return stroke or movement of the bed performs no printing operation and hence no special means to eliminate backlash need be provided although such could be readily added if considered necessary or desirable. The mechanism described is fully effective when it is needed, i. e. during the entire movement of deceleration of the bed when moving upon its printing stroke.

As previously stated, the invention may be embodied in printing presses which vary in detail and, without departure from the invention, the arrangement and design of its component elements may be considerably modified. One form thereof is illustrated in the accompanying draw ings by way of example.

In the drawings: a

Figure 1 shows in side elevation, in dotted lines, the frame and certain of the movable parts of a flat bed press, the bed, cylinder, bed oscillating means and the automatically operating mechanism for eliminating play or backlash upon the printing stroke of the bed all being shown in full lines;

Figure 2 is a view of the bed of the press as seen from below, the inertia device being illustrated;

Figure 3 is a section on line 3-3 of Figure 2;

Figures 4 and 5 are in the nature of mechanical diagrams, Figure 4 showing in perspective a portion of the bed, a member representing the cylinder, and the driving connection between bed and cylinder, the sliding rack mounted on the bed being illustrated in the position which is oocupies when the bed is in its acceleration phase while on its printing stroke and when moving upon the latter portion of its return stroke, and Figure 5 being a similar view, showing the relative positions of the sliding rack on the bed and the intermeshing gear segment on the cylinder when the bed is decelerating toward the latter part of its printing stroke.

The frame H) of the press and many of its operating elements, including the sheet feeding means and sheet delivery means, are either illustrated in dotted lines or are omitted and it will be understood that any suitable frame or sheet handling mechanism may be employed. The bed of the press is generally indicated at .I2 and this likewise may be widely varied in its details of construction. It is supported for movement in a horizontal plane and the means for efiecting its reciprocation or oscillation in this plane is, in part, illustrated in Figure l.

The shaft 13, extending horizontally and transversely of the press, has fixed upon it at one end a gear l4 adapted to be driven by power from any suitable source. A lever I5 is pivotally supported at (B for rocking movement about an axis parallel to the axis of shaft l3. Gear [4 and lever 15 are interconnected by means of a link H, link ll being pivotally connected to gear [4 at 18 and to lever l5 at l9. The upper end of lever I5 is connected by means of a link 29 to the bed l2. As the gear 14 rotates the bed will be advanced from the position in which it is shown in full lines in Figure l to the position in which it is indicated in dotted lines in this figure, passing under the impression cylinder 22 in such movement and cooperating with the cylinder in the printing of a sheet which is then superposed upon the cylindrical surface of the impression cylinder. From its dotted line position (Figure 1), the bed is moved on its return stroke by the mechanism described until it again reaches the position in which it is shown in full lines. This forward and return movement of the bed is rapidly repeated during the press operation, each successive printed sheet being withdrawn from the cylinder after a printing operation has been performed and delivered onto a pile by delivery mechanism generally indicated at D, and a fresh sheet seized by the cylinder grippers. Upon its printing stroke the cylinder rests directly on the bed, the narrow cylindrical cylinder bearing sur faces 24 and 25 at opposite ends of the cylinder 22 making rolling contact with the flat horizontal upward surfaces of the two elongated bearer members 25 and 21 mounted upon the bed. This arrangement is also of conventional char actor.

The means for imparting to the cylinder the oscillatory movement of the bed comprises an elongated rack 28 rigidly secured to the bed and extending parallel to its direction of movement, the teeth of this rack being in constant mesh with the teeth of a cylindrical gear 38 rigidly secured to the cylinder at one end thereof. As the bed reciprocates rotation of the cylinder about its axis is thus effected and, on the printing stroke of the bed, a sheet secured upon the surface of cylinder 22 will be brought into rolling contact with the upwardly facing surface of the type or printing member affixed to the bed.

In order to prevent slippage of the cylinder relatively to the bed, slurring of the sheet, and wear of the printing surface at the instant when slippage of the cylinder relatively. to the bed would normally take place, I provide a relatively simple mechanism. This includes a gear segment 32 which may be rigidly secured to that end of the cylinder remote from gear- 30- byv means such as bolts 33 which pass through slots 32!: in the seg ment, so that the angular position of the segment upon the cylinder may be adjusted when necessary. This mechanism also includes a rack 34 mounted upon that side of the bed I2 which is remote from rack 28, andso secured to the bed that it may be moved. relativelyto the bed, t a limited extent, in a direction parallel to the bed motion. Thus it is attached. to the bed by machine screws 35- which extend through slots 34a formed in the body ofthe rack. The upwardly extending teeth of the sliding. rack 34 mesh with the teeth of the gear segment 32. of the cylinder during the final portion or the printing stroke of the bed but do not intermesh while thebedis be ing accelerated. The inertia device or weight previously referred to is indicatedat 38 and is seen to comprise a member adjustably mounted upon a lever 39 which is pivotally connected at 43 to the bed, lever 33 extending transversely of the bed so that it may rock in a fore and aft direction to a limited extent. Forwardmovement of the lever 39 is terminated by-contact of member 38 with a transverse web portion In of the bed, a leaf spring-or othercushioning-device being provided to absorb any possible shock of impact between member 33 and member [2a. Motion of lever 39 in the opposite directionis limited by means ofstop42-andthe free end of this lever is adapted to be supported-by a horizontally extending member 12b whichis integral with or rigidly attached to the undersurface of bed l2. A helical tension spring 43 normally tends to maintain the lever and weight in the position in which these elements are illustrated in full lines in Figur 2.- The direction of the printing stroke of the bed shown in Figure 2 is indicated by the arrow P.

During the first half of the return stroke of the bed the lever 39' will occupy the position in which it is shown in dotted lines'in Figure2 but, during the deceleration period-atthe termination of" the return stroke, the weight and lever will mov to full line position, in which; position it will remain until the printing; stroke has been largely completed and bed decelerationhasbegun.

Movements of lever 39 are communicated to the sliding rack 34 by means of an intermediate lever 50 the end of thelonger arm of-which is connected by a link to, lever 33 atapointclos to the pivot 43, lever 51ibeing mounted for rocking movement about a pivot 52; A-short extension, or arm, 53 of lever 5G projectsintoa slot or recess formed in the inner face of the sliding rack 34 and communicates the rocking,v movements of lever 53 to the rack. By thearrangement of levers described the movements of'th'e inertia member 38, are communicated tothe sliding rack 34, the rack being moved longitudinally on the bed .I 2 when the.member.38.moves, and in a direction opposite to the direction in which the member 3zl moves. Because. of the mechanicalfladvantage of the system of levers employed the rack will be moved only a very-short distance as compared with the distance through which the inertia member will move, but-will be thrust longitudinally with great force against any object which it may engage. Thus, during deceleration of the bed on its printing stroke, when the teeth of rack 34 and gear segment 32 are in mesh. the following or rearwardly facing surface of each successive tooth of the sliding rack 34 will be positively and strongly thrust against the forwardly facing surface of that tooth of segment 32- which immediately follows, during a brief instant of time, the tooth t of rack 34-, for instance, being thrust against tooth t of the gear segment when these teeth occupy the positions in which they are shown in Figure 5, one end of the line of contact being indicated at M. The force transmitted to gear segment 32 is communicated through the cylinder (which is represented in Figures 4 and 5 by shaft 220) to main cylinder gear 30 and serves to maintain contact between each cylinder tooth and the following rack tooth at the pointof mesh, for instance between the rear or following face of tooth t and the leading face of: the-following rack tooth t alonga line of contact oneend of which is indicated at N. The pressureof'the-sliding rack againstthe teeth of segment32 isat all timessuiiiciently great: to maintain firm contact between the meshing: teeth of'gear 30 and: rack 28, despite any possible flywheel eifect of the cylinder.

While the bedis accelerating upon-its return stroke the inertia member 38-will continue to cocupy the position in which it isshown in dotted lines in Figure Z-and hence the cylinder will'be driven by the sliding rack 34 and close contact between meshing teeth of-- rack 28' and gear 30 maintained although, upon this'returnmovement of the bed, it is not important" that this action take place. As soon-asdeceleration onthenonprinting stroke begins; however, the member 38 will move to its full line position and the sliding rack will assume the position in-which-it is shown in Figure 4 with relation to-thebed; tooth-pres+ sure between the meshing teethof'rackand gear segment being relieved.

It will be appreciated that the design and'arrangement of the component elements ofthe invention may be considerably modified without sacrifice of benefit; To avoid-the application of torque to the cylinder, for-instance; the sliding and stationary racks may be- -both positioned=on the same side of thebed-of--the--pressi- Further-'- more, the mechanism disclosed, insomewhat different form, may be applied to-the type'of press in which the cylinderis-rotated at a-va-riable speed during the printing stroke. It may bead vantageously employed in association with a-press in which the cylinder-makes one complete revolution at a variable linear speed conforming to that of the type bed-and then remain-s-at-restduring the time when the type'bed isreturn-ingtoits initial position. The invention is 1 also of: utility when employed upon-a two revolutionpress in which the cylinder is rotated"continuouslyin one direction but at a linear speed'which-conforms to that of the type bed-during:the-printing stroke of the bed.

In the design ofaninertiadevice-for application to any certain press it will be'kept in mind that, even when'th'e press is tobe-operated at high speed, thefrictional forces opposing sli'p-be tween bed and cylinderare-substantial and that it is only necessary to provide an-inertia device of such capacity asto ;be, capable -ofapplying a force to the cylinder which when"added to'the frictional force opposing slip; cansuccessfullyre sist the momentum or-flywheel action of-th'e-oylinder. Hence the size ofthe inertia mechanism to be applied to the bed may-beminimized'and the weight of the press keptas low aspossiblez In calculating the force to be applied to the cylinder by the inertia mechanism it will also be 7 recognized that the force opposing cylinder fiywheel action developed by an inertia mechanism of the type disclosed herein will be at all times proportional to the inertia force developed by the cylinder itself. An inertia mechanism fully capable of resisting the momentum of the cylinder, and making no allowance for the effect of frictional resistance to slip between bed and cylinder may readily be designed, based upon this fact, but for reasons set forth it is preferred to take advantage of the normal resistance to slip between bed and cylinder.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a printing press, in combination, a printing couple, means supporting each member of said couple, respectively, for oscillatory movement, means for driving one member of said couple with an accelerating-decelerating motion, and gearing connecting said members to cause movement of one when the other is driven, said gearing including means responsive to change in velocity of one of said members for maintaining constant tooth contact and preventing relative movement of said members during a printing operation.

2. In a printing press, in combination, a print ing couple, means supporting the members of said couple for oscillatory movement, means for driving one member of said couple on its printing stroke with an accelerating-decelerating motion, and mechanism connecting said members to cause both to move when one is driven on its printing stroke, said mechanism including gearing and means responsive to change in velocity of one of said members for maintaining constant pressure of those teeth of said gearing which are associated with the driving member against the teeth associated with the driven member when said members are decelerating during a printing operation.

3. In a printing press, in combination, a pr nting couple, means supporting the members of said couple for oscillatory movement, means for driving one member of said couple on its printing stroke with an accelerating-decelerating motion, and mechanism connecting said members to cause both to move when one is driven on its printing stroke, said mechanism including a rack mounted upon one member, a gear mounted upon the other member, the teeth of rack and gear intermeshing during deceleration of said members while printing, and means responsive to change in velocity of one of said members for maintaining the teeth of rack and gear in constant driving engagement when said members are decelerating during a printing operation.

4. In a printing press, in combination, a printing couple, means supporting the members of said couple for oscillatory movement, means for driving one member of said couple on its printing stroke with an accelerating-decelerating motion, and mechanism connecting said members to cause both to move when one is driven on its printing stroke, said mechanism including gearing, an element mounted upon one member for movement forwardly with respect thereto, because of its inertia, when said member is decelerating on its printing stroke, and means connected to said element so as to be actuated thereby, for maintaining those teeth of the gearing which are associated with the driven elemher in constant contact with those teeth which are associated with the driving member when said members are decelerating during a printing operation.

5. The combination set forth in claim 4 in which said second means comprises a plurality of levers for multiplying the force developed by said inertia propelled element.

6. In a press of the type described, a cylinder having a gear rigidly mounted thereon, a bed having fixed thereon a rack the teeth of which mesh with those of the gear, means for driving the bed on its printing stroke with an acceleratingdecelerating motion, and mechanism associated with the bed and cylinder and responsive to change in velocity of the bed for maintaining the teeth of the cylinder gear in constant contact with the teeth of said rack when the bed is decelerating on its printing stroke.

'7. In a press of the type described, a cylinder having a gear rigidly mounted thereon, a bed having fixed thereon a rack the teeth of which mesh with those of the gear, means for driving the bed on its printing stroke with an acceleratingdecelerating motion, and mechanism including a second gear mounted upon the cylinder, a rack movably mounted on the bed, and inertia actuated means mounted upon the bed, for maintaining the teeth of said first gear and rack in constant engagement when the bed is decelerating upon its printing stroke.

8. In a press of the type described, a cylinder having a gear rigidly mounted thereon, a bed having fixed thereon a rack the teeth of which mesh with those of the gear, means for driving the bed on its printing stroke with an accelerating-decelerating motion, and mechanism for preventing relative movement of said bed and cylinder due to blacklash between teeth of said rack and gear when the bed begins to decelerate while moving on its printing stroke, said mechanism including a second rack mounted on the bed in parallelism to said first rack for limited longitudinal sliding movement, an inertia element mounted on-the bed for movement in a direction parallel to the direction of bed movement, means connecting said element and sliding rack whereby 1 the rack is moved rearwardly of the bed when the bed is decelerating on its printing stroke, and a second gear fixed on said cylinder and in mesh with said sliding rack.

9. The combination set forth in claim 8 in which said last mentioned means includes two inter-connected levers pivotally mounted upon and extending transversely of the bed, whereby a reduced motion is communicated to the sliding rack.

10. The combination set forth in claim 8 in which the cylinder gears are mounted upon the cylinder at the opposite ends thereof and the racks are mounted, respectively, upon the sides of the bed.

WILLARD M. 'POLLOCK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 962,962 Johnston June 28, 1910 1,430,274 Alger Sept. 26, 1922 1,973,464 Cox Sept. 11, 1934 

